title: Phosphorylation-dependent trafficking of GluR2-containing AMPA receptors in the nucleus accumbens plays a critical role in the reinstatement of cocaine seeking.
abstract: A growing body of evidence indicates that enhanced AMPA-mediated glutamate transmission in the core of the nucleus accumbens is critically involved in cocaine priming-induced reinstatement of drug seeking, an animal model of relapse. However, the extent to which increased glutamate transmission in the other major subregion of the nucleus accumbens, the shell, contributes to the reinstatement of cocaine seeking remains unclear. In the present experiments, administration of the AMPA/kainate receptor antagonist CNQX (0, 0.03, or 0.3 mug) into either the core or the shell of the nucleus accumbens before a systemic cocaine priming injection (10 mg/kg, i.p.) dose-dependently attenuated the reinstatement of drug seeking. Cocaine priming-induced reinstatement of cocaine seeking also was associated with increases in GluR2-pSer880 in the nucleus accumbens shell. The phosphorylation of GluR2 by PKC at Ser880 plays an important role in the trafficking of GluR2-containing AMPA receptors from the plasma membrane. The current results showed that administration of a cell-permeable peptide that disrupts GluR2 trafficking (Pep2-EVKI) into either the accumbens core or shell attenuated cocaine-induced reinstatement of drug seeking. Together, these findings indicate that changes in AMPA receptor-mediated glutamate transmission in both the nucleus accumbens core and shell are necessary for the reinstatement of drug seeking induced by a priming injection of cocaine. The present results also demonstrate that the reinstatement of cocaine seeking is associated with increases in the phosphorylation-dependent trafficking of GluR2-containing AMPA receptors in the nucleus accumbens.
authors.affiliation: Department of Pharmacology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
authors.forename: Katie R
authors.initials: KR
authors.lastname: Famous
authors.forename: Vidhya
authors.initials: V
authors.lastname: Kumaresan
authors.forename: Ghazaleh
authors.initials: G
authors.lastname: Sadri-Vakili
authors.forename: Heath D
authors.initials: HD
authors.lastname: Schmidt
authors.forename: Dale F
authors.initials: DF
authors.lastname: Mierke
authors.forename: Jang-Ho J
authors.initials: JH
authors.lastname: Cha
authors.forename: R Christopher
authors.initials: RC
authors.lastname: Pierce
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage; D019970:Cocaine-Related Disorders / Q000473:pathology* / Q000523:psychology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005518:Food Preferences; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism*; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D012646:Self Administration; D012694:Serine / Q000378:metabolism
chemical_list: D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; D012694:Serine; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D003042:Cocaine; C104722:glutamate receptor ionotropic, AMPA 2